Circuit breaker



Dec. 29, 19341. W DUB|L|ER 1,838,664

CIRCUIT BREAKER original Filed sept. 24, 192e 2 Sheets-Sheet 1 Dec. 29,1931. w. DUBILIER 1,838,664

CIRCUIT BREAKER original Filed spi. 24, 192e 2 sheets-sheet 2 \6Z l QZ,62

62, Inl/erm. 95. Ej Uhlham uluher y or -less diag'rammaticallyarrangements for' Patented Dec. 29, 1931 WILLIAMQDUBILIER, OFYNEWROCHELLE, NEW YORK CIRCUIT imEAxEn Application led September 24, 192,Serial No. 137,559. Renewed yMay 19, 1931.

This inventin relates to controlling devices; particularly devices forinterrupting or varying, if desired,.the current of an electric circuit.

An object of my invention is to provide a controllingdevice that will below in cost and relatively small size, and yet capable of operatingeffectively to open an electric circuit, or regulate a resistancetherein so as to alter the amount of current flowing, as may be needed.

Further objects and advantages of the invention are set forth in thefollowing description, taken with the drawings, which show several formsin which my invention is embodied. But the disclosure is illustrativeonly; and I may vary the constructions actually shown to the full extentwhich is consistent with the broad meanings of the terms in which theappended claims are expressed.

On said drawingsy Figures 1 and 2 are longitudinal sections of twoseparate forms of my invention for use ,asl circuit-breakers Figure 3 isadetail showing a modification of one of the parts; v

Figure 4 is a longitudinal section and Figure 5 a plan view of `a devicefor varying the resistance of a circuit; o

Figure 6 shows in perspective a container for the parts of the deviceshown in Figs.4 and 5; Y

y Figure 7 is a sectional view of another form of circuit breaker; v 1Figures 8, 9, 10, 11, and 12 show more breaking a circuit by means of aheated wire, and i i Figures 13 and 14 show similarly apparatus toreduce or increase resistance in a circuit.

The same numerals identify the same parts.

Figure 1 shows a controlling de vice designed to open anelectric circuitunder predetermined conditions. It-comprises a plug consisting of anupper part 1 of insulation and a lower part of conducting materialindicated by the numeral 2. In practice the part -1 will be the frontand the part 2 the rear, since the part 2 is inserted into a socketadapted to receive and mount the plug. The

part 1 has the form of a cup, closed at the bottom 3 except for acentral opening; and the part 2 is a threaded metal shell made fast tothe rim of the cup 1 at one end, and carrying at the other a closuredisk 4. Both the cup and the shell are preferably cylindrical.

In the exterior surface around the rim of the mouth of the cup I mayform a groove, and the edge of they shell 2 may be turned over as at 5to enter this groove tightly, and the cup and shell are thus securedtogether. The opposite endv of the shell has its edge turned over inwardas at 6 to engage the periphery of the disk 4; and between the threadson the shell 2, conveniently provided by spinning or lrolling or in anyother suitable fashion, and the inturned edge 6, the disk 4 is heldIfirmly in place. The disk is of insulation; but carries on its outerface a fixed contact 7 secured by a rivet 8 passing through the disk 4and fas- 70 tening to the inner face thereof a metal leaf spring 9. Thisspring is bowed away from the disk, presenting its convex side thereto;and it is engaged by the ends of a smaller metallic leaf spring 10. madefast at its center to a contact of carbon Aor other conducting Xmaterial 11 as by a rivet 12. The concave side of the spring 10 istoward the-disk 4, and the ends of the spring 10 pass through openingsin the spring 9 and are turned over to prevent 80 the ends of the spring10 from becoming disengaged from the spring 9. 'At the same time theends of the spring 10 may have some play if desired in the openings ofthe spring 9 which receive them; so that pressure on'the 85 contact 11can to some extent flatten the springs 9 and 10. Opposed to the fixedcontact 11 is a movable contact of the same material 11, held by a rivet12 to another metal spring 10, secured in the sameway to anothermetalspring'9, which is fastened by a screw or rivet 8 to theend of ametallic stem 13. The spring contact 9 and springlO attached to the stem13 are arranged with respect tothe stem in the same manner as the andthe second spring 10 has its convex face 100 presented in the samedirection. Hence when the stem 13 is moved towards the ydisk 4, thecontacts 9 and 11 can be made to come together, the contacts 11 comingtogether first by virtue of their closer proximity to each other thancontacts 9.

Inside the mouth of the cup 1 is a' fixed closuredisk 14 having acentral opening 15 for the stem 13, and the bottom 3 of the cup, whichis the front end of the plug has a similar opening 16. The interior ofthe cup is thus separated from the interior of the shell, and the insideof the shell 2 constitutes a chamber wherein the springs 9 and 10 andthe contacts 11 are located. The stem 13 has a collar or washer 17thereon abutting against a stop 18, and inside the cup is a s ring orresilient element 19 between this colar and the disk 14. This springtends to separate the contacts 11. Normally, however, the contacts areheld in engagement with each other by a thermostatic element 20 having alatch 21 to engage the collar 17, and encircled by a resistance orheating coil 22. This coil is connected to the stem 13 at one end, andextends through the cup l to unite -with the shell 2 at the other. Theelement 20 is affixed in any suitable way to the inside of the cup, asby fastening it on the closure 14. It has the form of a strip made oflayers of brass and steel, or other metals of different coeiicients ofexpansion. Such strips are well known and generally referred to underthe name of bi' metal. Hence, vin operation, if the stem is pushed inagainst the spring 19, the contacts 11 will be forced into engagementwith each other; and the springs 9 and 10 may yield and permit thecontacts 11 to come together squarely and engage evenly over the entiresurfaces. With the contacts 11 in such relation, the latch 21 will holdthe stem and keep the contacts from separating. But if too much currentowsthrough the coil 22, the heating effect of the current on the strip20 will cause .this strip to bend away from the stem. pulling back thelatch 21 to release the collar 17 and a'llow the stem to move upwardunder the force of the spring 19. Thus the circuit through the contacts11 will be broken. Of course strip 2O will have the layer which expandsthe more on heating disposed on the side towards the stem, so as to bendawa from it when the latch 21 is to be pulled back, as with an excess ofcurrent. The upper end of the latch may be bevelled, so that the collar17 will push this latch resiliently to one side as the stem is forcedinward of the plug.

This type of controlling device is adapted for circuits on power linesinstead of the usual kind of fuse which burns out 011 excess current.The circuit is through the threaded shell of the socket which receivesthe shell 2; the shell 2, coil 22, stem 13, contacts 11, contact 7 andfinally the central contact of the fuse socket to the other conductorjoined to the fuse socket. This plug will not be destroyed by excesscurrent, but will only inter rupt the circuit. It can then be resetmerely by pushing in the stem 13, and the circuit restored. At the sametime the cost of manufacture is comparatively little. The contacts 1lmay be of carbon, and will absorb the heat of the spark when the circuitopens, since they are the last to separate.

Figure 2 shows another form of my invention, very similar to that justdescribed, except that instead of the small carbon contacts 11, twoblocks orvdisks 11 and 11 of carbon or other material arc used. One ofthese rests on a metal plate 23` turned up around its rim at 24 to gripthe block ll. This plate 23 is disposed against the inner face of thedisk 4, and has a boss 25 which projects through a central aperture inthe disk to constitute the outer central Contact of the plug. In thisboss is a spring 26 encircling a stem 27 carrying a head 28, the stemand head, with the upper part of the spring being within a centralopening 29 of the block 11 The other block 11 is carried by the stem 13.This stem has a head 28 on its inner end; and the block 11 on the stemhas an opening 29 with an inside shoulder 31, against which is aninsulating gasket or packing 32. The head 28 is engaged by this gasket,so that as the stem rises, the block 11 thereon rises with it. On saidlock may be put several perforated disks 33 of similar material,surrounding the stem 13; and on top of these disks 33 is an ellipticalspring 9', pressing with one side against these disks 33. Both sides orhalves of this spring 9 encircles the stem 13, the lower half loosely,but the upper half is secured on the stem between two fixed collars 34.In the cup is an electromagnet coil 35, with a plunger 36 of magneticmateriall impelled outward by a sprmg 37 in the coil 35. This coil isjoined to the stem 13 and to the shell 2 by a wire 22". To bring thecontacts 11 and 11 together, the stem 13 is forced inward to enable theplunger 36 to engage the upper end of a rib or a stop 18 on the stem,and thus the plunger acts as a catch to hold the contacts l1 and l1 inengagement. In this condition, the plug will have the head 28 pressingresiliently against the head 28 and the upper block y 11 held by thespring 9 acting through the disks 33 firmly against the lower block 11.When sufficient current flows through the coil 35 to overcome the spring37, the catch 36 is pulled back, and the stem released. The stem is thenmoved up by the spring 9. I may bevel the outer end. of the catch, sothat, when the stem 13 is forced inward, the stop 18 Will push back thecatch, but the spring 37 will immediately return it over the top of thecatch. Of course the catch 36 must be polyg onal or otherwise to engagethe inside of the coil 35 so that it will not turn in same. This plugmay act so that when the coil 35 retracts the catch 36 the compressedspring 9 will impel the stem 13 upward with a slight bound, rstseparating the heads 28 and 28 and then lifting the upper block 11 andblocks 33. Then before the stem 13 and the block thereon can again dropto bring the heads 28 and28 and the blocks 11 and 11 .togetheragaim thespring 37 acts to force out the catch136, because the magnet 35 isnowdeenergizedand this catch projects under the stop 18 and the stem andthe parts carried thereby remain in raised position. Such action isimportant when the plug is used with the shell 2 lowermost, orhorizontally, while if the shell 2 is uppermost, gravity will alwayskeep the contacts 11 and 11" apart after the coil acts. The currentflows through the stem 13 and heads 28 and 28 and the contacts 11 and11, which are of carbon, for example, absorb the spark when the plugopens the circuit. The moment the stem is released, the pressure on theblocks or resistance elements 11', 11" and 33 is reduced, and theresistance through them increased. The arc is thus more quicklyextinguished.

Figure 3 shows how in place of a resistance coil to heat thethermostatic element 20 I can use a heating block 38 which is preferablyof carbon. This block 38 is secured to the strip by bands 39. On theblock 38 is put a conductive plate to which a conductor is attached. Thebands 39 may be of metal, and between the bands and the plate 40 is aplate or sheet of insulation 41. Also, block 38 should preferably not beso wide as the face of the strip, which is shown in edge view,

so that the sides of the block and the bands fore.

are spaced apart.r Then current must flow to the strip through the block38 and not through the bands 39. When the block grows warm, the latch 21will be pulled back as be- The strip 20 may be set up on any suitablesupport in the plug, as at 14.

Figures. 4, 5, and 6 show a controllingdevice for gradually reducing thecurrent in a circuit and then opening the circuit altogether. Here Ishow a trough-shaped metal container 42, open at the bottom, with ledgesor shelves 43 inside at each end, and extended extremities 44. Insidethis container is a resistance element of carbon or other substance 45,resting at its ends on the shelves 43. It is flush with the upper edgesof the container and ends 44; and in its upper surface is a depression46.YA Insulating strips 47 separate the. sides of the carbon 45 from thesides of thecontainer 42. Movable contacts, such as brushes 48, whichmay be attached to the conductorsof a circuit, may engage the ends 44,and thus put the whole length of the carbon element 45 out of operation,the circuit being closed through the container 42. As the bushes moveupon the carbon towards each other and out of Contact with thecontainer, the carbon member 45 comes into the circuit, introducingresistance, and decreas-` ing the current. The portion of the element 45in circuit increases as the brushes appreach, because current\must flowfrom one brush to the adjacent end of the container, then through thecontainer to the other end by way of the carbon element again to theother brush to the opposite side of the circuit. When the brushes reachthe middle of i gaging an opening in the support. This element 50 may beprismatic in shape. It is engaged'by a V-shaped contact 52, withcurledup edges 53, attached to a metallic rod 54.

This rod may carry a split cylinder 55, the

edges of which press on the sides of the contact 52. The lower end ofthe rod 54 may be thinned to provide a shoulder against which thecylinder is placed, the cylinder having an opening in its side to givepassage to the thin end of the rod. The parts are all seen in edge viewin Figure 7. When one end of a circuit is connected to the element 5()and the other to the contact 52, then the resistance will be least andcurrent greatest when the contact 52 is forced down to engage the wholeside surface of the element 50 and touch plate 49. As the rod 54 islifted, the member 50 is included in the circuit more and more,increasing the resistance and reducing the current.

In Figure 8, I show at 56 a support bearing a flexible metallic member57 carrying a movable contact 58. Adjacent the contact 58 is a fixedcontact 59. Between two fixed suports 60 is a wire or conductor 61,making a hermal member the length of which will increase upon heating.To the wire -61Y are connected the conductors of a circuit 62 and wires63 unite the ends of the wire 61 to the member 57 and contact'59. A link62 of insulating material unites the wire 61 and member 57. The member57 has a normal set to move the contact 58 towards the contact 59, butthe link 62 holds it back. When the wire 61 heats and lengthens, thespring member 57 is allowed to move the contact 58 against the contact59 and short-circuit the wire 61. This device may be used for flashinglamps. When the wire 61 is shortcircuited, it cools and contracts,pulling on `the member 67 to break the circuit. Hence 63 willintermittently light up and go out.

Figure 9 illustrates the same device, with a longer wire 61, passingover idler pulleys 64 between the conductive supports 60. rIhis longerhot wire gives more expansion.

In Figure 10, the supports are mounted on an insulating member or cover65, and the middle of the wire 61 is connected to the member 65 by aspring 66. At 67 is a rod mounted to slide in a bearing 68. Encirclingthis rod is a spring 69, between one of the bearings 68 and a fixedcollar 70. A latch 71, on a pivot 72, engages the collar and holds therod 67 in position to force the member 57 to hold the contact 58 againstthe Contact 59, the spring 69 now being compressed. Another latch orlever 71, also on a pivot 72 is connected by a link 74 at one end to thelever 71 between the catch 73 and pivot 72 and a similar link isconnected to the second lever 71 between its ends, and to the wire 61adjacent the point of attachment of the spring 66. The tension of thewire 61 offsets the spring 66, but as the wire heats and gets longer,the spring. 66 can lift the levers 71 and spring 69 then acts to movethe rod 67 and release the member 57 to open the circuit. The wire 61then cools, and the operator can again close the circuit by pushing on aknob at the end of rod 67.

Figure 11 shows a fixed contact 59 con nected to a bellcrank lever 75 ona pivot 76,

vand to one side of the circuit. The opposite side of the circuit isjoined to a sliding contact 58', one end of which is engaged by a hook73 on a latch 71, mounted on a pivot 72. A link 74 of insulatingmaterial joins the levers 71V and 75 together. The end of the lever 71is connected to a spring 77 attached to a fixed point, this lever havinga projection 78 of insulation to which the spring is affixed; Contact 58is mounted on a rod 79, affixed to a support 80, and carries a spring 81to draw back the contact 58 and open the circuit. The contact 58 mayhave a bore 82 in which the 4rod 79 is received, so that the contactslides on the rod. Heating of the wire 61 results in lifting the catch71.to re lease the contact 58.

In Figure 12 the hot wire 61 is enclosed in a tubular sleeve or housing83, with ends 84, all of insulation. The ends of wire 61 pass throughthe ends 84, and a link 74, joined to the middle of the wire 61 passesthrough an opening in the sleeve 83V and is connected to a cord 85passing over an idler pulley 86. The other end of this cord is attachedto a fiexible member 87 fixed to a support 88, and a spring 89 attachedto the end of this support and to a fixed point tends to pull themember` 87 and cord 85 and keep the cord taut. Oh a rod 67 sliding inbearings 68 is av contact 90, and a fixed contact in proximity theretois joined by a wire 91 to one end of the wire 61. The pulley 86 ismounted on a journal or pivot 72 and rigid with the pulley is a. latch71, having a hook 73 to engage a collar 70 on the metallic rod 67, aspring 69 encircling this rod as in Figure 10 between the collar 70 andone of the bearings 68. This bearing may be joined to one side of thecircuit and the other end of the wire 61 to the remaining side. `Whenthe wire 61 heats and expands, the spring 89 can pull the member 87 toturn the pulley 86, moving the latch 71 torelease the collar 7 O and rod67 so that the spring 69 can cause the contact 90 to move away from thecontact at the end ofV conductor 91, and opens the circuit.

Figures 18 and 14 show a row or pile of carbon or other resistance disksor blocks 31 between end members or plates 92. The ends of each row orpile is joined to a circuit by conductors 62', and the other end ispressed upon by a point 98 on a spring or flexible member 94, fixed to asupport 95. The member 98 is also connected through a thermal member orhot wire 61 to another circuit by conductors 62. In Figure 13, heatingup of wire 61 allows the member 94 to compress the elements 81 andreduce resistance and increase current; while in Figure 14, the heatingof the wire 61 produces the opposite effect.

Having described my invention, what I believe to be new and desire tosecure and protect by Letters Patent of the United States is 1. Afuse-socket device for an electric circuit comprising a fixed contact, amovable contact, a thermal member to hold said contacts in engagement,and an element to separate the contacts when released by said thermalmember, said contacts being adapted to introduce resistance into thecircuit while moving away from each other.

2. A fuse-socket device comprising a yielding Contact, a resistanceelement associated therewith, a movable contact comprising a stem,resistance element associated with this Contact, a spring to hold saidcontacts and said elements in engagement, and a heating coil and thermalmember to release the stem and allow the contacts and resistance elements to separate.

2. A circuit breaker enclosed in a socket plug comprising relativelymovable contacts part of which are of relatively greater resistance andarranged to open later than the others. t

4. A fuse-socket device comprising metallic fixed and movable contacts,and fixed and movable contacts of carbon mounted to separate after themetallic contacts.

5. A fuse-socket device comprising metallic iixed and movable contacts,and. fixed and movable contacts of carbon mounted to separate after themetallic contacts, at least one of the metallic contacts beingyeldable.l n

6. In an electric circuit, a plug type breaker device comprising a pairof vnormally engaged contacts in said circuit, a second pair of contactsin shunt with said first pair of contacts and bi-metallic .meansassociated vwith said circuit for controlling the operation of bothpairs of said contacts in a predetermined order.

7. In an electric circuit, a plug type breaker device\comprising a pairof normally engaged contacts in said circuit, a second pair of contactsin shunt with said first pair of contacts, a latch device holding saidcontacts in engagement yand a bi-metallic means associated with th`e\circuit for operating said latch device to control the operation of bothaidpairs of contacts in a predetermined orer. v v

8. In an electric circuit, a plug type breaker device comprising a pairof flexible contacts connected in said circuit, a spring deviceoperating to cause said contacts to disengage, a latch device forholding said contacts in engagement against the action of saidv springand `loi-metallic means associated with said circuit for operating saidlatched device to permit said springs to operate said contacts intodisengagement. v A

9. In an electric circuit, a plug type breaker device comprising a fixedcontact, a movable contact, means for normally urging said contacts intodisengaged condition, a latch device for normally holding said contactsinlto engagement against the operation of said last mentioned means, abi-metallic means associated with said electric circuit operating saidlatch into a non-operating position whereby said first mentioned meansis operative to operate the contacts into disengaged condition and meansfor varying the resistance of said circuit as said contacts are opened.

10. In an electric circuit, a plug type breaker device comprising astem, an inflexible contact and a flexible contact carried by said stem,an inflexible contact and a flexible contact positioned opposite saidfirst mentioned contacts respectively and arranged to be engagedthereby, said flexible contacts being l arranged to disengage beforesaid inflexible contacts disengage.

11. In an electric circuit, a plug type breaker device comprisng a stem,an inflexible contact and a flexible contact carried by said stem, aninflexible contact and a flexible contact positioned opposite said firstmentioned contacts respectively-and arranged to be engaged thereby, said`flexible contacts being arranged to disengage before said inflexiblecontacts disengage, means normally urging said stem to carry said firstmentioned contacts from engagement with said second;` mentionedcontacts, a latch device holding said stem in 4operative position inwhich said contacts are in engagement and a thermal responsive means foroperating said latch device from holding said stem whereby said firstmentioned means operates said stemv to disengage said contacts.

12. In an electric circuit, a fuse plug t pe breaker device comprising astem, an in exible contact and a flexible contact carried by saidstemfan inflexible contact and a flexible contact positioned oppositesaid first mentioned contacts respectively and arranged to be engagedthereby, said flexible contacts being arranged to disengage before saidinflexible contacts disengage, means normally urging said stem to carrysaid first mentioned contacts from engagement with said secondmentionedI contacts, a latch device holding said stem in operativeposition in which said contacts are in engagement and a bi-metallicresponsive means for operating said latch device from holding said stemwhereby. said first mentioned means operates said stem to disengage saidcontacts.

13. In an electric circuit, av plug type breaker device comprising astem, an inflexible contact and a flexible contact carried by said stem,contacting means positioned opposite the said contacts and arranged tobe engaged thereby, said flexible contact being `arranged to disengagefrom said contacting means before said inflexible contact disengagesvtherefrom.

In testimony whereof I aflix my signature.

WILLIAM DUBILIER.

